James and Amanda Roberts kiss their son, Nathan, as Amanda Redding, M.D., right, and Gina Whitney, M.D., prepare to take him to surgery, where he received his long-awaited heart transplant. (photo by Anne Rayner)

After eight months, 11 days at the Monroe Carell Jr. Children's Hospital at Vanderbilt, the 18-month-old patient got a donor heart in the early hours of Jan. 13. He got to trade in his device, the Berlin Heart, which his family nicknamed “Bernie.”

Nathan's transplant took about eight hours.

“The new heart looked very happy inside Nathan's chest, and it was working very well,” said Karla Christian, M.D., the lead pediatric heart surgeon who performed the procedure.

The Berlin Heart, similar to other left ventricular assist devices used in adults, is the first of its kind for infants and children.

Nathan was the first patient in Tennessee to get the device, which requires special approval from the U.S. Food and Drug Administration.

About 200 infants and small children in the United States have used the German-manufactured device.

A plastic tube, connected to the heart's major vessels, funnels the body's blood through a pumping mechanism that sits outside the chest.

“Bernie has saved Nathan's life. He has served his purpose, but we are more than happy to trade it in and bring Nathan home,” said Nathan's mother, Amanda Roberts. “It's been a long time; a lot longer than we anticipated.”

Nathan Roberts, here on his way into surgery, has spent nearly half his 18 months connected to a ventricular assist device called the Berlin Heart. (photo by Anne Rayner)

Debra Dodd, M.D., director of Pediatric Heart Transplant, who is Nathan's cardiologist, said he was doing well in the 48 hours following his transplant.

“He looks super. We couldn't have asked for better,” Dodd said.

Dodd said he could leave the hospital about two weeks after surgery, which brought tears to Nathan's father.

“We've been here so long, and we have so many friends here,” said James Roberts. “But we're so excited.”

Nathan's situation was made more compelling by his long wait for a donor heart. The average wait time is about one to two months.

“When the transplant team comes in smiling, it can only mean one thing,” said James Roberts, about the news that a donor had been found.

“I didn't believe it was actually going to happen — not until they came out and told us the transplant was done.”

Nathan has endured a lot during his young life, starting with the early days after his birth when doctors discovered his heart was misshapen. At four months, he had surgery to close a hole between the heart's chambers and to repair a misshapen valve. He got very sick again.

In May, Nathan was put on ECMO (Extracorporeal Membrane Oxygenation), a system that pumps blood and oxygen throughout the body.

But infants only can be on ECMO for about two weeks because their risks increase for kidney failure, stroke and infections. The tiny patients also must be sedated and on a ventilator.

The surgical team with Vanderbilt's Pediatric Heart Institute implanted the Berlin Heart in Nathan on May 27.

“The success with Nathan illustrates that it's a very good device for small infants and children when chosen for the correct patient,” said Christian, adding that under the right circumstances she would use the device again.

“The Berlin Heart is essential to the survival of infants and young children who need long-term mechanical support prior to transplantation.”